Rivers and streams descend rapidly the steep slopes, creating waterfalls such as that of The Petrified Trees, where the high limestone content in the water “froze” ancient tree trunks. Elsewhere, water has carved more spectacular gorges, known locally as Cahorros. The most famous effect of water erosion in the area are the numerous underground caves, in particular that of Nerja, declared a National Monument, as well as pit cave on the Maroma mountain.